Dynamo-electric machine.



PATENTED MAY 5, 1908.

W. L. WATERS. DYNAMO ELECTRIC MACHINE.

APPLIOATIOI FILED DEC. 13, 1906.'

WI REESE-S:

brush holder frame or yoke.

UNITED 'sTArgs PaTENT OFFICE.

WILLIAM 1/. \I-XTERS. OF MILWAUKEE. \YIStOXSlXi ASSIGXOR TO NATIONAL BRAKE & ELEV TRIP tOMlAXY, Olr. MIIJAYAITREE. WISCONSIN. (.URPURQVFIUN Ul" \YlhUUNSlN.

DYNAMO-ELECT'RIC MACHINE.

Specification of Letters Patent.

Patented May 5, 1908.

Application filed December 1906. Serial No. 347,612.

l\lih\'aukee. in the county of Milwaukee and mate of is'consm, have mvented a certain new and useful Improvement in Dynamo Electric Machines, of which the following is a full', .clear, concise, and exact description, referen eing had to the accompanying drawings forming a part of this specification.

My inv ent relates to dynamo electric machines, pa icularly to brush holder mechanism, the main feature residing in means for preventing sparking between the commutator and the machine frame;

\Yhen machines are used as motors on circuits in which there is sudden variation in voltage, as,- for instance, in street railway work, thereis a-tendency for the commutator to flash over to the frame of the machine, particularly to .the bearing. frames which are usually quite near the commutator, and my invention contemplates the introduction of a shield of insulating material between the commutator and bearing frame, this'preventing such stray currentflow.

My invention will be readily understood. by reference to the accompanying drawings in which I Figure 1 is an end view of the brush holder mechanism and of a bearing frame on which the brush holder is mounted; Fig. 2 is a sectional View taken on line 2-2 of Fig. 1.

I have. shown part of an armature 1 mounted on the armature shaft 2 whose one end is shown journaled in a bushing 3 which lines the bearing frame 4. Between the bearing frame and the armature the commutator 5 is mounted on the armature shaft. The brush holder frame 6 1s mountedln any a suitable manner at the edge of the bearing frame adjacent to the commutator, and the brush frames 7 are supported from this In the c011- struction shown the yoke 5 has the slots '8 on which may be claimed the insulating spool sections 9 and 10, the arms 11 extending from the brush frames 7 extending through the spools to be engaged at their other ends by the locking nuts 12 and 13 which also clamp between them the terminal lug 14. The brush frames are arranged over the commutator so that the brushes 15 theretor ran on astre'et railway circuit.

in bear'in suitable position on the commutator, spring actuated arms 16 b ing here shown tohold the brushes in engagement with the commutator.

I'nless provision ismade, there will be at times sparking between the commutator segments and the bearing frame 4, particularly when the voltage changes very suddenly which would be the case when themo- TO prevent such sparking, I interpose a shield 16 of insulating material having the shape as shown in Fig. 1, this shield having the slots 17 registering with the slots 8 of the brush yoke and which slots also receive the spool section 9. Thus when the brush frames are clamped to the yoke, the shield 16 will also be clamped and held in osition, and the lower end sections thereo being interposed will be held in position to extend clownwa-rdly to interpose between the commu tator and the brush yoke and bearing frame end. Thus sparking between the COIIIHHF tator andother frame arts is prevented.

I do not wish to belconstruction and arrangement herein shown, as my invention maybe applied to brush holder mechanisms of any construction, the main feature being interposit-ionof an insulating shield between the commutator segments near the engaging brushes and the machine frame or other parts deslred to be kept insulated from the commutator or brushes.

united to the precise I claim as new and desire to secure by Letters Patent:

In a dynamo electric machine, the combination of an armature and commutator terial having slots registering with the slots in' the brush yoke, clamping studs securing the brush frames to the brush voke and causmg said shicld to be simultaneously clamped.

thereto, said shield of insulating material bemg interposed between the brush frames and brush YOKQS to electrically separate the secmy name this 7th day of December A. D., tion of the commutator engaged by the 1906.

brushes from the brush yoke andbearing I I frame; thus preventing sparking between the WILLIAM A 5 ccmmutator and. brush yoke and bearing Witnesses:

frame. EDNA B. BURDioK,

- In witness whereof, I hereunto subscribe S. W. GLOVER. 

